Whenever a doctor prescribes a period with limited or no weight bearing on a single leg or foot, in order to avoid pain or improve healing, the present invention provides an appliance to support the single leg of a patient in a rearward, suspended state while standing on the patient's other leg. This appliance assists the patient in the prevention of weight bearing. The appliance is designed for use with a below-the-knee cast, a similar strap-on orthopedic boot, an orthopedic shoe, a tennis shoe, or a bandaged foot. The appliance transfers the load of the suspended leg onto the patient's upper torso and is designed to work in conjunction with a walker or crutches. If the patient loses balance, the appliance includes a breakaway safety fastener designed to open at a pre-determined force. If necessary the patient can use the muscles of the suspended leg to disengage the sling at the breakaway safety fastener, which provides the patient with immediate use of the injured leg to regain balance. Afterward, the safety fastener is easily restored to operational use.
As discussed in U.S. Pat. No. 5,882,321, Leg Sling and Abdominal Belt, Fisk (1999), few ambulatory leg slings exist of a prior art. However, an ambulatory leg sling providing a means to disengage and provide the patient immediate use of the injured leg to regain balance has not been disclosed or suggested in the prior art. The Breakaway Leg Sling incorporating the breakaway safety fastener accomplishes this feat. U.S. Pat. No. 2,543,847, Leg sling For Treatment of Unilateral Leg Diseases, Halstedt (1951), disclosed an ambulatory leg sling for use with crutches and provided for suspension of a single leg in a rearward, elevated position. U.S. Pat. No. 2,543,847 was designed to treat a special type of disease, specifically Legg-Perthes disease. In the treatment of this disease, the patient does not wear a cast on the foot and leg but must avoid weight bearing. Mr. Halstedt did not design the Leg Sling For Treatment of Unilateral Leg Diseases to securely, safely encase and ergonomically interface with a below-the-knee cast but rather interface only with the patient's shoe; this leg sling does not provide a slip free and secure means of encasement for the below-the-knee cast. And, if the patient loses balance while using the Leg Sling For Treatment of Unilateral Leg Diseases, the patient might trip and incur additional injury. As a result, the Halstedt leg sling has not been adopted by the medical community as a means to avoid weight bearing on the foot or ankle healing in a below-the-knee cast or soft orthopedic shoe.
U.S. Pat. No. 2,543,847 utilized a single strap with two terminal ends. One terminal end was attached to a single buckle, and the free end of the strap passed through the same buckle twice more to fashion two loops. One loop was placed over the shoulder of the patient on the side opposite of the suspended leg, and the shank of the leg rested in the bottom of the second U-shaped loop thereby providing a means of suspending the leg. U.S. Pat. No. 2,543,847 had several limitations. First, during gait, the U-shaped loop had a tendency to slip along the shank of the leg. Although arm slings successfully used the U-shaped loop as the suspensory means, the U-shaped loop was less effective for suspending the leg because the leg cannot be held as stationary during motion. If the loop slipped during gait, the patient was at risk of bearing weight on the mending leg. Hallstedt recognized this limitation, and he designed a specialized shoe stirrup to minimize slippage. To make the stirrup, a first and second end of another shorter strap were riveted to opposite sides of the suspending U-shaped loop. The new loop comprised the stirrup, and the new loop formed into the stirrup was lodged forward of the heel of the shoe. However, the patient must wear the shoe to complement the stirrup. Without the shoe's heel, the stirrup was ineffective and the loop slipped. Thus, the stirrup will not work with a cast. The cast is smooth on the plantar side of the foot and does not provide a protruding heel. A cast boot or cast shoe that the patient might wear was not designed with the protruding heel needed to effectively work with the shoe stirrup. Thus, the Leg sling For Treatment of Unilateral Leg Diseases remained an ineffective device for improving the mobility of the patient wearing the leg cast. Further, those skilled in the art, namely Podiatrists and Orthopedic surgeons, have not recognized the Leg Sling For Treatment of Unilateral Leg Diseases as an effective and safe post surgical device to improve the patient's mobility following surgeries that require the leg cast and a period without weight bearing, such as a bunion correction where the first metatarsal bone of the great toe must be surgically severed, straightened, and re-positioned. Second, the issue of the patient's safety was not considered in the design since the patient had no means to instantly, effortlessly break apart the Leg Sling For Treatment of Unilateral Leg Diseases to prevent a potential fall with the assistance of the injured leg. Third, to prepare the sling apparatus for use from a sitting position, the patient had to lift the leg and insert the foot through the suspending loop. Once the loop was positioned around the shank of the leg, the specialized shoe stirrup was positioned underneath the heel of the shoe. This process was awkward, time consuming, and difficult in cramped conditions such as the driver's seat of a vehicle.
U.S. Pat. No. 5,882,321, Leg Sling and Abdominal Belt, Fisk (1999), provided another ambulatory leg sling, but a sling designed to accommodate the cast. As seen from the drawings of this prior art, the leg is suspended in a near vertical position with the suspended foot slightly to the rear of the other leg. An abdominal belt was provided to distribute the load of the suspended leg about the patient's lower torso placing the burden of the load on the hips of the patient. Shoulder straps were included to prevent the upper leading edge of the abdominal belt from rolling and slipping downward. As stated in the claims, the leg sling provided the U-shaped loop in which the sole of the suspended foot contacted the foot receiving means. The upper ends of the U-shaped loop could be anchored at a plurality of potential locations on the abdominal belt.
U.S. Pat. No. 5,882,321 had several shortcomings. First, the sling did not provide a means to instantly, effortlessly break apart to prevent a potential fall with the assistance of the injured leg. Second, similar to Hallstedt's Leg sling For Treatment of Unilateral Leg Diseases, the loop remained the means of suspension, and the sole of the foot rested in the bottom of the U-shaped loop. Third, while the suspended leg remained in a near vertical position, the load distribution carried by the abdominal belt remained more over the hip on the side of the suspended leg. Fourth, the leg sling apparatus required a considerable amount of time to completely remove and return to use. Fifth, the abdominal belt produced discomfort in a large patient, especially when sitting, by constraining the abdominal region.
Another device of the prior art is U.S. Pat. No. 5,911,696, Integral Strap Handling Device For A Leg Cast, Coates (1999). U.S. Pat. No. 5,911,696 provided a device for the patient to maneuver a cast, especially a heavy above-the-knee cast, about a bed or similar place of rest. The device was comprised of four straps. The instep strap crossed over the top of the forefoot; the complementing sole strap crossed underneath the sole of the foot. The heel strap crossed behind the heel of the foot. Two rings were used to bind the terminal ends of the three straps together. One ring bound the terminal ends on the lateral side of the ankle, and the other ring bound the terminal ends on the medial side. A means of adjusting the length of each strap was provided. Attached to the instep strap on the top of the forefoot was the assist strap, which provided a means for the patient to grasp the assist strap and maneuver the leg about while resting on the bed or sofa. However, the Integral Strap Handling Device For A Leg Cast did not provide a means to secure the foot apparatus to a load bearing means, and the position of the assist strap on the forefoot was of no value for this purpose. Further, there is no expressed or implied suggestion in this art to modify the Integral Strap Handling Device For A Leg Cast for other than its intended purpose, especially since it is a complete functional unit. However, even if necessary modifications were made to the Integral Strap Handling Device, to include removal of the assist strap and incorporation of an anchor means on the reward section of the heel strap, the Integral Strap Handling Device would produce an inferior result for distributing the forces about a user's foot while in a rearward, suspended state. In the rearward, suspended state, any anchor modified to fixedly attach to the heel strap must pull against the first and second rings on the sides of the foot with a force equal to the weight of the load, and all forces born by the suspended foot would be transferred through these two rings and about the band encircling the forefoot which is comprised only of the instep and sole straps. With only the forefoot completely encircled, the constant pressure applied at this one location would increase the user's discomfort since all forces born by the foot would be distributed about this single location. For a user wearing only a bandage covering the foot, this would be quite discomforting. Furthermore, the assist strap could snag an object during the ambulation cycle and cause a fall; removal of the assist strap would but be necessary to improve the user's safety but would render the Integral Strap Handling Device inoperable for its intended purpose.
Another device of the prior art is U.S. Pat. No. 3,739,772, Resilient Harness Device For A Walking Cast, Ennis (1973). The apparatus was comprised of a body harness adapted to extend diagonally across the user's torso depending from the user's shoulder on the side opposite the leg cast. Attached to a holding member at the terminal ends of the body harness strap was the first end of a lead strap. A second holder member was fixedly attached to the second end of the lead strap. Engaged to the second holding member on the lower end of the lead strap was a swivel eye spring connector attached by its releasable end. The other non-releasable end of this swivel eye spring connector was fixedly attached to the first distal end of a pull spring; the second distal end of the pull spring was fixedly attached to a second swivel eye spring connector by its non-releasable end. The releasable end of the second swivel eye spring connector was engaged to a holding member on a foot band encircling the forefoot of the walking cast. Adapted to the user, the lead strap was forward of the user's body. When the walking cast was in contact with the ground, the spring was stretched and potential energy stored. During the next forward step of the ambulation cycle, the spring assisted the patient with lifting the leg and cast thereby reducing the strain on the muscles of the leg. During this portion of the ambulation cycle, the load was distributed onto the user's shoulder. In order to modify the Resilient Harness Device For A Walking Cast to a functional ambulatory leg sling, numerous modifications would be necessary. However, there exists no suggestion in this art, expressed or implied, to modify the Resilient Harness Device For A Walking Cast into a functional leg sling. Assuming the minimal necessary modifications are performed, these modifications necessitate removal of the spring, removal of one swivel eye spring connector, reversal of the remaining swivel eye spring connector to orient the releasable end at the lower end of the lead strap, incorporation of a lead strap length adjustment means, and incorporation of a pad into the body harness to improve the user's comfort and mitigate the pressure on the shoulder. However, even if these modifications were made, the single foot band would produce an inferior result when suspending the leg. The use of the single band would increase discomfort when the leg was suspended for long periods, especially for the user with only a bandage covering the foot. With only the single band encircling the forefoot, the constant pressure applied at one location would increase discomfort since all forces born by the elevated foot are distributed about the single location. Further, these modifications would render the Resilient Harness Device For A Walking Cast inoperable for its intended function.
Another device of the prior art is U.S. Pat. No. 5,860,944, Hoffman, Jr. (1999). Hoffman, Jr. disclosed the Back Support Apparatus that essentially included a pair of shoulder straps, a waist belt, two guide tubes, a pair of heel connectors, a pair of support lines, and a pair of coil springs integrated into each of the support lines. The Back Support Apparatus assists the user with back support as an aid in performing manual labor requiring frequent bending from the waist. Adapted to the user, each support line was engaged to a heel connector attached to the user's feet; each heel connector was configured to couple with the respective heel of the shoe on each foot. Fixedly attached to each heel connector was a connection eye similar in design to an eyebolt. The connection eye was fixedly attached to the heel connector on the upstanding heel brace with the connection eye oriented upward and in line with the attached support line. The lower end of the wire rope support line was fixedly attached by a loop formed from the wire rope passing through the connector eye and then secured to itself with a suitable clamp. As designed, the connector eye was a rigid, non-pivotal anchor for securing the support line; the opposite end of each support line was adapted to the user's shoulders through the shoulder straps. Two straps with hook and loop fastener were included on each heel connector for snugly securing the heel connector to the user's shoe. If the heel connector is integrated as a foot receiving means into an ambulatory leg sling, the patient must wear a shoe since the heel connector is configured to couple with the respective heel of the user's shoe. A cast is typically wider than a shoe, and the upstanding heel brace would interfere with the cast properly seating into the heel connector. It would be necessary to expand the width of the heel connector to accommodate the cast; however, this would make the heel connector too large to snugly fit around a user's shoe or bandaged foot and thereby produce an inferior result. Although U.S. Pat. No. 5,860,944 does not state the material composition of the heel connector, the drawings suggest a rigid material such as a metal alloy or a hard plastic. In order to be an effective foot receiving means for an ambulatory leg sling, the foot receiving means must be adjustable in size to accommodate either a cast or a bandaged foot and be flexible to enhance comfort; the heel connector described does not afford these benefits. Further, the wire rope integrated into the support line and fixedly attached by loop and clamp to the eye connector must be removed from the heel connector, and removal of the wire rope would render the heel connector inoperable for its intended function. Yet, even if these modifications were performed, the heel connector would produce an inferior result for suspending the leg because of the force distribution problems described previously when the forces are distributed about a single location on the foot. And, the heel connector would not comfortably, securely remain on the foot during extended periods of bed rest due to its hard material structure and limited means of being secured to the shoe. Thus, the heel connector would not provide a suitable foot receiving means for the ambulatory leg sling.